Supplemental oxygen supply system

ABSTRACT

An oxygen supply system for aircraft passengers in which a solid oxygen-yielding composition is stored in a hermetically sealed container. An electrical ignition system initiates thermal decomposition of the composition and removes a fusable seal from the container. Oxygen gas is released upon decomposition of the solid composition. A testing circuit is provided to automatically test the operativeness of the ignition system and the fusable container seal. A plurality of containers, linked to a common activating and testing system, provide oxygen for an aircraft passenger compartment.

United States Patent [72] Inventor Richard L. Vernon Glendale, Calif. 21App1.No. 810,656 [22] Filed Mar. 26, 1969 [45] Patented Oct. 26, 1971[73] Assignee Lockheed Aircraft Corporation Burbank, Calili.

[54] SUPPLEMENTAL OXYGEN SUlPlPLY SYSTEM 8 Claims, 6 Drawing Figs.

[52] U.S. Cl 23/281, 23/221, 128/1423, l28/203,222/3 [51] 1nt.C1 1801]7/00 [50] Field of Search 23/281, 221; 128/203, 142.3;222/3 [56]References Cited UNITED STATES PATENTS 2,331,944 10/1943 V on Pazsiczkyet a1. 65/2 2,558,756 7/1951 Jackson et al. 23/281 2,998,018 8/1961 Becket a1. 222/3 X 3,089,855 5/1963 Bovard 23/281 X 3,482,568 12/1969 Bovard23/281 X Primary Examiner-Joseph Scovronek Assistant Examiner-Barry S.Richman Attorneys-George C. Sullivan and Ralph M. Flygare ABSTRACT: Anoxygen supply system for aircraft passengers in which a solidoxygen-yielding composition is stored in a hermetically sealedcontainer. An electrical ignition system initiates thermal decompositionof the composition and removes a fusable seal from the container. Oxygengas is released upon decomposition of the solid composition. A testingcircuit is provided to automatically test the operativeness of theignition system and the fusable container seal. A plurality ofcontainers, linked to a common activating and testing system, provideoxygen for an aircraft passenger compartment,

PATENTEDUCT 2 6 IHYI SHEET NF 4 INVIiN'I'OR. RICHARD L. VERNONPATENTEDDBT 26 m1 SHEET 2 OF 4 FiG 4 INVI'IN'I'UR. RICHARD L. VERNON('u'll 2 Ageni's PATENTEDum 2s IHTI 6 1 5,250

sum u 0F 4 INI IiN'I'OR. RICHARD L. VERNON Z/ vzg au SUPPLEMENTAL OXYGENSUlPFlLY SYfiTlEMl BACKGROUND OF THE INVENTION l. Field of the InventionThis invention relates to a system of supplying gaseous oxygen from asource of solid-state oxygen to passengers in an aircraft. Moreparticularly, this invention relates to a system for producing gaseousoxygen by thermal decomposition or a type of combustion of a solidoxygen-yielding compound and for automatically providing the oxygen topassengers in an aircraft upon sudden decompression of the passengercompartment.

2. Description of the Prior Art An emergency supply of oxygen isrequired for passengers in an aircraft at high altitude in case of aninadvertent cabin pressurization failure. Prior art apparatus andmethods for providing oxygen for vehicles other than aircraft includemodular sodium chlorate oxygen generators which, upon the combustion ofsodium chlorate, yield gaseous oxygen. These prior art generators arenot hermetically sealed and are susceptive to an exchange of atmospherewith an aircraft passenger compartment. The gaseous oxygen is piped toan oxygen mask located adjacent a recipient of the oxygen. Theapplication of this use to aircraft passenger compartments involvesseveral problems. One such problem is caused by water vapor in the airwhich is forced in and out of the sodium chlorate bottles under varyingatmospheric pressure conditions. The water vapor chemically affects thecompressed sodium chlorate and causes it to become ineffective as asource of oxygen. Prior art solid state oxygen generating systems arealso of inherently low reliability in that it is difficult to test theoperativeness of all the working parts such as the igniter and mostimportantly the efficacy of the oxygenproducing chemical. Primarilybecause of this reliability problem, prior art solid state oxygenproducing systems have been mostly confined to underwater uses such asin submarines, where it is possible to store spare generators andwherein weight is not as crucial a factor as it is in an aircraft.

The present emergency oxygen supply system comprises multiplehermetically sealed containers of a combustible solidstate oxygen sourcewhich provide oxygen to a plurality of receptacles in the passengercompartment of an aircraft. A remotely controlled circuit is provided tosimultaneously remove the container seals and to initiate the combustionprocess. A test circuit is also provided to test the operativeness ofthe seal and the ignition circuits.

Accordingly, it is a principal object of the present invention toprovide an emergency solid-state oxygen supply for aircraft passengers.

Another object of the present invention is to provide an oxygen supplyfor aircraft passengers which comprises a system of multiple bottles ofan ignitable oxygen-producing chemical, wherein said bottles expeloxygen through a manifold to a passenger compartment.

Yet another object of the present invention is to provide multiplebottles of ignitable sodium chlorate to cabin receptacles in aircraftwherein said bottles are hermetically sealed until ignition of thesodium chlorate.

Still another object of the present invention is to provide anelectrical test circuit for bottles of combustible oxygenproducingcompound, said bottles remaining sealed until actual use thereof.

SUMMARY OF THE INVENTION In one of its broadest aspects, the inventedlatent oxygen supply system comprises a hermetically sealed containerhaving an outlet port; a combustible oxygen-yielding compound locatedwithin the container and means for igniting the oxygen-yielding compoundand for removing the hermetic seal from the container. Conduit means areconnected to the container and conduct oxygen gas to an outlet locatedadjacent a recipient of the oxygen. Circuit means are provided forautomatically testing the operativeness of the ignition means and thehermetic seal of the container.

One of the primary advantages of the described oxygen supply system isits reliability which is assured by a unique electrical testing circuitthat tests the operativeness of the seal and of the ignition circuit.Another advantage of the system is that the oxygen-producing apparatusis not centralized thus the hazards of a tire of oxygen gas areminimized. Because multiple oxygen generators are used, no centralplumbing system is required thus affording a weight saving over priorart oxygen systems. Still another advantage of this system over priorart systems is that the bottles containing solid-state oxygen are sealedso that moisturedaden air cannot enter; this feature prevents thechemical degradation of the oxygenproducing chemical compound and thusinsures reliability.

Yet another advantage of the invented latent oxygen bottle is thatatmospheric pressure within the sealed bottle is maintained atapproximately 15 pounds per square inch (p.s.i.) thus allowing theignition system to function at the same pressure as that at which it istested, this assures uniform ignitions at all altitudes.

The novel features which are believed to be characteristic of theinvention, both as to its organization and method of operation, togetherwith further objects and advantages thereof will be better understoodfrom the following description considered in connection with theaccompanying drawing in which a presently preferred embodiment of theinvention is illustrated by way of example.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevation view, partiallysectioned, of the latent oxygen supply bottle;

FIG. 2 is a diagrammatic view of the fiusable hermetic seal;

FIG. 3 is a diagrammatic view of the oxygen generator and mask in anaircraft fuselage;

FIG. 4 is a diagrammatic view of a system of multiple oxygen masks forsupplying passengers;

FIG. 5 is a schematic of the electrical circuit for testing and remotelyactivating the oxygen supply; and

FIG. 6 is an elevation view, partially sectioned, of an alternateembodiment of the oxygen supply container.

DESCRIPTION OF THE PREFERRED EMBODIMENT Oxygen of sufiicient purity forphysiological use may be obtained by the thermal decomposition orcombustion of chlorates and perchlorates in a suitable apparatus. Theselfregulated thermal decomposition of these chlorate candles" is due tothe combustion of finely divided oxidizable material intimately mixedwith a chlorate such as sodium chlorate. An inorganic binder is added tothe mixture and a peroxide such as barium peroxide is added to inhibitthe evolution of chlorine during the combustion process. Theseconstituents are mixed and heated until the chlorate begins to melt; themolten mass is then cast to give candles of the desired size and shape.The above-described chlorate candles are well known in the art as asupply of solid-state"' oxygen and are not claimed a part of the presentinvention. The significant features of the present invention include anew and improved container for chlorate candles and a remotely activatedsystem of supplying aircraft passengers. from a multiplicity of suchcontainers along with a test circuit for testing the efficacy of theoxygen generating apparatus as will be described in detail hereinafter.

With reference to FIG. ll, there is shown a solid state source ofphysiologically pure oxygen comprising a combustible oxygen producingcast chemical composition 10 within a thinwalled container 12.Typically, chemical composition 10 comprises an oxygen-containingcompound such as potassium or sodium chlorate intimately mixed with .apowdered oxidizable metal such as iron. Powdered iron is preferably usedin the present embodiment. An alkaline oxidizing agent is introducedinto the mixture to eliminate the formation of free chlorine; bariumperoxide (B302) has performed satisfactorily for this function. Powderedfiberglass is then added to the mixture as a binder. These constituentsare heated until the chlorate begins to melt, are then cast into a moldof a desired configuration, compressed, and allowed to harden to form acandle." A typical formulation for such an oxygen producing candle is asfollows:

The candles of this composition have a density of about 2.45 grams permil and will liberate about 34 percent of their weight as gaseousoxygen. It is within the scope of the invention to provide candleshaving other oxygen-yielding compounds such as other chlorates orperchlorate compound.

One end of the candle contains an ignition area 14. This area comprisesthe same materials as the rest of the candle but contains a differentratio of components. A typical ignition area mixture contains 60 percentsodium chlorate, percent iron, 10 percent barium oxide and 10 percentfiberglass. When heated locally by an electrical initiator to thereaction point the iron combines with part of the oxygen in the chlorateto form iron oxide. The heat generated by this reaction raises the localtemperature of the sodium chlorate and breaks it into oxygen and sodiumchloride. The process may be represented by the equation:

With reference again to FIG. 1, a chlorate candle (10) is housed in thecontainer 12. The container 12 is a generally thin-walled cylindricalcontainer of a metal such as stainless steel. The metal of the containershould be heat resistant to withstand the combustion temperatures of thechlorate candle. In the presently preferred embodiment of the invention,stainless steel walls of 0.019 inch in thickness are utilized and aninsulating material 15 is packed around the chlorate candle within thecontainer 12.

The insulating material 15 prevents a portion of the heat of combustionof the chlorate candle from reaching the container walls and causingthem to become excessively hot. The insulating material must also bechemically inert; that is, when material 15 is exposed to hightemperatures no noxious fumes must be evolved. One such insulatingmaterial that has been successfully used is leached fiberglass choppedinto short lengths and packed into the container 12 around the chloratecandle.

Leaching of the fiberglass removes soluble constituents therefrom bypercolation, thereby rendering it clean for this purpose.

At various locations within the container and adjacent the containerwall, quantities of silica gel 16 or other hygroscopic material arelocated to absorb water vapor that may leak into the container. Thesilica gel aids in keeping the chlorate candle free from moisture whichwould chemically react with the composition of the candle and cause itto flake and to become ineffective as a source of oxygen.

The cylindrical container 12 has a top surface 13 into which is sealablyinserted an outlet plug 18 having a conduit 19 which allows oxygengenerated within the container to flow out therethrough and into tubing38. A fusible metallic disc 20 is located within the conduit 19 in sucha manner that the conduit is closed off and the container 12 iseffectively sealed. The fusible disc 20 is made of a low melting pointelectrically conductive metal such as an alloy of lead and tin or thelike. When a sufficiently high electric current is passed through thedisc, its temperature is raised sufficiently to cause it to melt andthus to open the conduit 19. To protect it from the effects ofenvironmental water vapor, a thin polymeric corrosion-resistant coatingis applied to all the surfaces of the disc. This coating prevents theformation of discontinuities therein which would prevent the passing ofan electric current which could cause the disc not to fuse when thecurrent is applied. The coating also prevents gross corrosion anddeterioration of the disc which could cause the seal of the container 12to be broken. The disc 20 is mounted within the outlet plug 18 upon acylindrical member 22 which can conveniently be a clamping nut. Whenmounted upon the member 22, the disc 20 is horizontally disposed acrossthe conduit 19 thereby effectively sealing the conduit. The disc 20 isso constructed that in case ignition of the candle starts before thedisc is fused the oxygen pressure from within the container can puncturethe disc.

As best seen in FIG. 2, electrical contact is made to the underside ofdisc 20 by electrical leads 23 which are attached to the disc bystainless steel tabs 24.

An electrical connector 28 is sealably attached to the top 13 ofcontainer 12 adjacent the outlet plug 18. Electrical leads 23 and 26 areled into the interior of container 12 through electrical connector 28.As has been previously described, leads 23 provide electrical current tothe fusible disc 20 and are attached to the disc by means of stainlesssteel tabs 24. Disc 20 is fused by passing approximately 0.4 amperesthrough tabs 24 for 500 milliseconds. This current is lower than thatrequired to initiate the combustion of the candle so that ignitioncannot proceed until the disc is fused. Leads 26 provide electricalcurrent to the ignition area 14 of the chlorate candle by means of anembedded electrical element 17. Upon passage of sufficient current,i.e., 0.5 amperes, into the ignition area 14, the enriched compositionis heated locally by the igniter element 17 until its ignitiontemperature is reached and the combustion process commences. Combustionof the chlorate candle then proceeds at a uniform rate with theformation of breathable oxygen gas. The ignition section can be ignitedwith an electric squib, or an embedded heating wire.

In the alternate embodiment of the invention shown in FIG. 6, the oxygensupply container 12 is provided with a threaded neck portion which isadapted to sealably retain a mounting plate 52. The outlet plug 18 andelectrical connector 28 are permanently mounted upon the mounting plate50 with orifices being provided in the plate for electrical leads 23 and26 and for conduit 19. A threaded locking nut 54 is threaded onto thethreaded neck portion 50 of the container. When the locking nut 54 isconnected to the neck portion 50 the mounting plate 52 is sealablyretained within the neck portion of the container by the locking nut.Thus, there is provided a quick change assembly for the oxygen supplycontainer. When the chlorate candle (I0) is exhausted, locking nut 54 isunthreaded and the mounting plate 52 with the outlet plug 18 andelectrical connector mounted thereon is removed from the neck portion50. A new container can then be provided and the locknut can again bethreaded onto its neck portion. Only new electrical leads 23 and 26 arenecessary to make the unit operative.

Referring to FIGS. 1, 3, 4 and 6, upon initiation of the combustionprocess within the oxygen generator, oxygen gas is evolved and expelledfrom the generator at a pressure of approximately 1 psi. The generatoris remotely activated by energizing lead wires 27, which run to thepilots compartment. The oxygen flows out of the generator container 12through the conduit 19 of outlet plug 18 and into manifold 34 viainterconnecting tubing 38. The rate and volume of oxygen flow can beregulated by properly contouring the chlorate candle. In a typicalconstruction of the invention, the chlorate candle has a cup shape andis 3 inches in diameter and 2.5 inches deep. The oxygen generated bysuch a candle is expelled from the container at a low constant pressureof approximately l p.s.i.

Manifold 34 conducts the oxygen to a location adjacent a mask storagecompartment 36 within the passenger companment 37 of the aircraft. Whennot in use, the masks 66 are stored within a compartment 36 which islocated above the passenger seats. As best seen in FIG. 3, the maskstorage compartments are closed by an electrically operated door 62,hereinafter more fully described. The electrical input signal thatignites the chlorate candle composition 16 and fuses the disc 26 alsocauses the door 62 to open. The mask door 62 is opened by a solenoid Mwhich is energized by an electrical circuit in response to the closingof aneroid switches 66, shown in FIG. 6. The door 62 also may be causedto open by means of a manually operated switch 62 in the pilotscompartment.

The opening of door 62 allows the oxygen masks 66 to be lowered fromcompartment 36 to a position adjacent passenger seats. It is asignificant feature of the present invention that immediately uponinitiating the oxygen generating process and opening door 62, oxygen isavailable immediately to passengers at a constant low pressure. Theoxygen masks are connected to oxygen manifold 36 by plug-in couplings 35which incorporate metering orifices that control the even distributionof oxygen flow.

In the presently preferred embodiment of the invention, a plurality ofoxygen generators are deployed throughout the passenger compartment ofan aircraft. In a typical construction, each oxygen generating bottle(viz, container 12) is approximately 4 9%, inches high and 3.0 inches indiameter and can provide three passengers with oxygen for approximatelyl5 minutes which is the time taken for an aircraft to descend from40,000 feet to 10,000 feet in an emergency descent. Thus, the oxygensupply for the passengers is decentralized with every three passengerssharing a single oxygen generator. It is, of course, within the scope ofthe invention to vary the capacity of the oxygen generators so that moreor fewer passengers could use them for a longer or shorter period oftime.

With reference to FIG. 5, there is shown the activation cir suit for theemergency oxygen electrical system. Power for the emergency oxygenelectrical system is derived from a DC standby bus 66, via circuitbreaker 6ll, which is protected from power loss during emergencyconditions. A manual bypass switch 62 is located on the flightengineer's control panel 67 and in the normal" position, power isapplied to dual aneroid controlled switches 66. Whenever the cabinpressure falls below a predetermined amount (i.e., pressurecorresponding to an altitude of 12,500 feet) aneroid switches 66 willclose, thereby activating a timer 66. Two aneroid switches (64) areprovided for reliability and they are connected in such a way thateither one, or both, may activate the timer 66 when the cabin pressurelimit is reached. Timer 66 provides a IO-second delay in activating thesystem. Timer 66 closes a circuit to ground 65 through normally closedtimer switch 66, at the end of the lO-second delay interval. Ifnecessary, an additional 5- second delay can be obtained by manuallyactivating timer 66, to provide 15 seconds total delay for rectifying atemporary condition. The additional S-second delay is obtained bymanually activating timer 66, by means of switch 69, which thereuponchanges from its normally closed circuit condition to anopen-circuit-to-ground condition for an interval of 5 seconds. if cabinaltitude decreases to below 12,500 feet within the 10 (or optionally thesecond time delay period, the system returns to its normal state withoutactivating the oxygen system or releasing the masks 66. When thiscorrective action occurs, timers 66 and 66 are automatically reset totheir normal state.

The activation circuits form a continuous loop to maintain completesystem activation if a single parted wire occurs and are normallygrounded to prevent inadvertent operation of the system. These groundsare automatically removed at the completion of the timer delay period.When the circuit is activated, an indicator light goes on on the pilotscontrol panel 67.

Following a cabin depressurization condition, the complete system can bemanually operated by actuating manual switch 62 on the control panel 67.

mun

Upon a cabin depressurization, aneroid switches 66 are closed and poweris simultaneously supplied to the oxygen generator initiator circuit andto leads 26, through the fusible disc 26 through leads 22 and to thesolenoid-operated latch 66 of the mask compartment.

The DC voltage appearing on bus 66 is supplied both to the passengerunit module 63 and to the control panel 67. The interconnection betweenthe passenger unit module 63 and the control panel 67 is viamultiple-contact electrical connector 73. interconnection to the variousremaining passenger unit modules is via cable 76 comprising lines911-67. Test circuits are completed to the passenger unit module 63 vialines 92, 93, and 96, to diodes 96-1161.

The system test circuit utilizes solid-state, microminiature integratedcircuit sensors 76 and 72 to check circuit continuity. Each sensor(76-72) has its own indicator light 79 and 611, respectively, whichilluminates when continuity is interrupted. These circuits are tested bya wheatstone bridge balancing process. Resistance measured across eachof the sensor circuits is balanced with a known resistance 76-77 and 66.If the circuit is impaired, the higher resistance of the faulty circuitwill cause the appropriate sensor to signal the lamp driver unit 66, or62 and cause the OXYGEN CHECK light 66 or MASK DOOR DROP CHECK light 66on the: control panel not to illuminate, indicating a fault hasoccurred. Each sensor also has its own indicator light 79 and 66,respectively, which illuminates when continuity is interrupted.

When the OXYGEN SYSTEM TEST switch 76 is placed in the test position,the aneroid switches 66 are actuated to the closed position, thusactivating the lO-second timer 66. At the same time, power is applied tothe individual sensors 76 and 72 which are connected across eachgenerator initiator (26) and mask or latch solenoid 611. The sensor, 76or 72, puts out a low-magnitude pulse of short duration to preventsystem activation. If continuity is complete through all sensor units,the OXYGEN CHECK light 66 and the MASK DOOR CHECK light 66 on thecontrol panel 67 will. be illuminated. These check lights are driven vialamp driver transistors 62 and 66, respectively.

Should a fault be detected at any one of the oxygen generators orsolenoids (e.g., 26 or ill, etc), the associated sensor will signal thelamp driver unit 66 or 62 and cause the appropriate check light on thecontrol panel 67 to become illuminated indicating a fault has occurred.This fault can be readily located by means of the individually visiblefault indicator lights 79 and 611 at each use point. Actuation of theSENSOR LAMP TEST switch 92 located in the control panel 67 provides avisual illumination check of all indicator lamps in the system. Tocomplete the system test, a TIMER CHECK light 96 is provided on thecontrol panel 67 which will be illuminated 10 seconds after initialactivation of the SYSTEM TEST switch 76, indicating proper functioningof the ten second timer 66. Activation of the FINE-SECOND DELAY switch69 on the control panel 67 will extinguish the timer check light 96 fora S-second interval after which this light will again be illuminated toindicate proper functioning of the 5- second timer 66. illumination ofthe timer check light 96 also assures circuit continuity through theaneroid switch 66.

A MASK DROP test switch 63 is provided on the control panel 67 which,when activated, opens the oxygen mask doors via solenoid 611, and allowsthe masks to drop for maintenance purposes, or for demonstrations,without initiating the oxygen generators.

In operation of the emergency oxygen supply system, a cabindepressurization causes aneroid switches 66 to close and after aIO-second delay activates the initiator circuit. Current is suppliedsimultaneously to fusible disc 26, generator initia tor and mask doorsolenoid M. The initiator is heated locally until the combustion processis initiated which then proceeds at a uniform rate while liberatingoxygen gas. At the same time, the disc 26 is fused thereby opening theconduit l9 and allowing oxygen to flow through a manifold 36 to theoxygen masks 66. The solenoid latch. 56 is simultaneously \ninrm nILAopened allowing the mask compartment door 42 to be opened and the masks40 to be removed. The oxygen supply continues until the chlorate candleis exhausted.

There is thus provided an oxygen supply system for aircraft passengerswhich is safe, and reliable. One significant advantage of the presentsystem is that the oxygen generators remain hermetically sealed untilused thus preserving the ef ficacy of the oxygen-producing chloratecandles. Also because of the sealing of the generators, the pressurewithin them remains constant and they operate at the same pressure atwhich they are tested; this assures uniform activation of the system atall altitudes. A further advantage of the present system is that theoxygen is supplied at a relatively low pressure, thus in case of a firethere is not blowtorch" effect as in the case with prior art systems.Another advantage of the invented system is the novel test circuitprovided by which the operativeness of the generator initiator, thefusible disc and the mask door solenoid can be tested byresistance-balancing circuits.

Although this invention has been disclosed and illustrated withreference to particular applications, the principles involved aresusceptible of numerous other applications which will be apparent topersons skilled in the art. The invention is, therefore, to be limitedonly as indicated by the scope of the appended claims.

What is claimed is:

1. An oxygen supply system comprising:

an hermetically sealed container having an outlet port;

a fusible disc sealably located in said outlet port and responsive tothe application of an electrical current therethrough to result in thefusing thereof and thereby leave said outlet port substantiallyunobstructed;

a combustible oxygen-yielding composition located within said container;and,

electrical means for sequentially fusing said disc and initiatingcombustion of said oxygen-yielding composition.

2. The oxygen supply system of claim 1 wherein said combustibleoxygen-yielding composition comprises:

sodium chlorate in the range of 75 to 85 percent by weight;

powdered iron in the range of 5 to 15 percent by weight;

powdered glass fibers in the range of 2 to percent by weight; and,

barium oxide in the range of 2 to 6 percent by weight.

3. The oxygen supply system of claim 1 wherein said electrical meanscomprises:

a source of electrical power;

a resistance heating element embedded in said composition and,

electrical circuit means interconnecting said power source with saidresistance heating element and said sealing member whereby said sealingmember will be caused to fuse and unseal said outlet port and thereaftersaid composition will be heated to its ignition temperature.

4. The oxygen supply system as defined in claim 1 wherein said fusibledisc includes:

a thin, polymeric, corrosion-resistant coating applied to all surfacesthereof.

5. The oxygen supply system as defined in claim 1 wherein saidoxygen-yielding composition is formed into a contoured candle, the shapeof which results in a substantially constant pressure of gaseous oxygenbeing generated as combustion proceeds from a given end thereof.

6. An oxygen supply system for an aircraft comprising:

a hennetically sealed container having an outlet port;

a disc of electrically conductive low-melting-point metal sealablyengaging the outlet port of said container;

a combustible oxygen-yielding composition located within said container;

insulating material located within said container and surrounding saidcombustible oxygen-yielding composition to substantially prevent heatfrom reaching the container walls' remoteiy controlled means forapplying an electrical current to fuse said disc and thereby open saidoutlet port and thereafter ignite said oxygen-yielding composition; and

a manifold connected to said outlet port of said container forconducting oxygen gas from said container to an outlet in the passengercompartment of said aircraft.

7. The structure as defined in claim 6 wherein said insulating materialcomprises chopped fiberglass that has been leached.

8. The structure as defined in claim 6 wherein quantities of ahygroscopic material are situated within said container adjacent thewalls thereof.

lOlO07 0165

2. The oxygen supply System of claim 1 wherein said combustibleoxygen-yielding composition comprises: sodium chlorate in the range of75 to 85 percent by weight; powdered iron in the range of 5 to 15percent by weight; powdered glass fibers in the range of 2 to 10 percentby weight; and, barium oxide in the range of 2 to 6 percent by weight.3. The oxygen supply system of claim 1 wherein said electrical meanscomprises: a source of electrical power; a resistance heating elementembedded in said composition and, electrical circuit meansinterconnecting said power source with said resistance heating elementand said sealing member whereby said sealing member will be caused tofuse and unseal said outlet port and thereafter said composition will beheated to its ignition temperature.
 4. The oxygen supply system asdefined in claim 1 wherein said fusible disc includes: a thin,polymeric, corrosion-resistant coating applied to all surfaces thereof.5. The oxygen supply system as defined in claim 1 wherein saidoxygen-yielding composition is formed into a contoured candle, the shapeof which results in a substantially constant pressure of gaseous oxygenbeing generated as combustion proceeds from a given end thereof.
 6. Anoxygen supply system for an aircraft comprising: a hermetically sealedcontainer having an outlet port; a disc of electrically conductivelow-melting-point metal sealably engaging the outlet port of saidcontainer; a combustible oxygen-yielding composition located within saidcontainer; insulating material located within said container andsurrounding said combustible oxygen-yielding composition tosubstantially prevent heat from reaching the container walls; remotelycontrolled means for applying an electrical current to fuse said discand thereby open said outlet port and thereafter ignite saidoxygen-yielding composition; and a manifold connected to said outletport of said container for conducting oxygen gas from said container toan outlet in the passenger compartment of said aircraft.
 7. Thestructure as defined in claim 6 wherein said insulating materialcomprises chopped fiberglass that has been leached.
 8. The structure asdefined in claim 6 wherein quantities of a hygroscopic material aresituated within said container adjacent the walls thereof.